Add pipe operator, with-update, retry/fallback, reason, parallel, trace, contract, deploy

Implements 8 new language features:
- |> pipe operator: a |> f desugars to f(a), left-associative chains
- with record update: let b = a with { field: val } — non-destructive struct update
- retry/fallback: retry N times { ... } fallback { ... } with counter-based loop codegen
- reason: AI inference primitive calling soma /v1/chat/completions at runtime
- parallel: concurrent execution block returning a Map of named results via threads
- trace: zero-cost observability block emitting TraceBegin/TraceEnd with ms timing
- requires: precondition annotation on fn, emits ContractCheck bytecode at entry
- deploy: deployment-as-syntax posting to soma /v1/deploy at runtime

All features thread through lexer → parser/AST → codegen → runtime interpreter.

crates/el-types/src/checker.rs

@@ -191,6 +191,13 @@ impl TypeChecker {
                     });
                 }
             }
+            Stmt::Retry { body, fallback, .. } => {
+                for s in body { self.check_stmt(s); }
+                if let Some(fb) = fallback {
+                    for s in fb { self.check_stmt(s); }
+                }
+            }
+            Stmt::Deploy { .. } => {}
         }
     }
 
@@ -476,6 +483,12 @@ impl TypeChecker {
                     }
                 }
             }
+
+            // Engram-specific expressions
+            Expr::With { base, .. } => self.infer_expr(base),
+            Expr::Reason { .. } => Type::String,
+            Expr::Parallel { .. } => Type::Unknown,
+            Expr::Trace { .. } => Type::Unknown,
         }
     }